What is the friction rate in pipes?

Size of pipe? Water pressure? Why do you want to know? If this is a new installation can you give me more information? Back to you, Tom

Friction also depends on the material of the pipe.

Good point Brian,
A iron pipe produces more production more friction than a plastic one. Regards, Tom

You gave us NO information in your question.

To figure out friction in water pipe, engineers use so called "Hazen Williams" formula. To work with the formula, you need to know the following four values: 1. Material of pipe 2. Flow 3. Friction Head loss 4. Size of pipe. In addition, each installed fitting has a "friction loss" value assigned to it. So you also need to know what fittings are used and how many of them.

Hope that helps. Back to you / Milo